Okay, so If you are wearing a mask which while it covers your nose & mouth; yet is not tight either from around the nose or cheeks; then it is neither protecting you nor people around you.
And, if after that you get infected It is not the fault of the mask.

The reason why N95/N99 have been designed to cover your entire face without leaving a leak is to prevent spread.

The commonly offered reason for not wearing tight masks by people is - they are suffocating or choking.
As a HCW, I & countless of my colleagues have worn these masks everyday without suffocating or choking & they have helped to protect us.

The only reason why masks won’t work are either because they are not worn at all, or not worn properly or are not properly fitted or the choice of material is incorrect.